Tool-feed mechanism for wood-screw machines



Feb. 6, 1923. 1,444,433. H. l.. SMITH.

TOOL FEED MEOHANISM FOR WOOD SCREW MACHINES.

FILED JAN. 3,1922.

Y 25 controlled by Patented Feb. 6, 1923.

aan y PATENT ortica.-

HENNY L. SMITH, or WATERBURY, CONNECTICUT, AssIeNon To THE n. J.' IuaNvmLN MACHINE COMPANY, or WATERBURNCCNNECTICUT, a CORPORATION or CCN- NECTICUT.

TOOL-FEED MECHANISM FOR WOOD-SCREW MON i Application led January 3, 19'22. Serial No.v 526,496.

To all 'whom zt may concern.'

Be it known that I, HENRY L. SMITH, a citizen of lthe United States, residing at VVaterbur in the county of New Haven and V State of onnecticut, have invented a new v and useful Im rovement` in Tool-Feed -Mechanism for growl-Screw Machines, of which the following is a specication.-

This invention relates to those' machines threads -on screw blanks. In automatic wood screw machines the threadcutting tools vare fed and returned along each blank several times. At the end of each feedthe cutting edge of the tools. are turned out from the blank so that they may bereturned for the.

next cut. Aftereach return the cutting edges are' turned in toward the axis of the blank slightly further than during the previous forward feed so as to increase the depth of the cuts. turn movements are v the contours of the cuts arexcontrolled byprofile cams, and the depths of the cuts are depth cams acting through the profile cams.

- The object of the present invention is to so design the 'tool *controlling mechanisms of a screwmachine of this 'class that two threads maybe cut by tool controlled by a single feed cam, a single profile cam and asingle depth cam, the two thread cuts starting on dametrically o posite sides of the blank at the same d1s" tance from the point.v

Tol accomplish this with-one tool, in the embodiment of the vinvention illustrated, l the rotatoryfeed cam is mounted on the' feed cam shaft so as to have a-bodily movement' longitudinally thereof after every return of. the tool, whereby afterone returnl thetool commences to cut at one locality and after.

the next return it commences.v to cutat'another'point, thus. alternating 1n making the 45, two thread cuts. v

' In shows afront elevation ofso muchl of a Wood screw machine 'as is .necessary to tan understanding of the present invention.

Fig. 2 shows a `vertical section of the mecha-l lane lndicated by the.

nismtaken on the dotted line 2-2 on 1g. 1. Flg. 3 shows a vertical section on the dotted line 3-3 on Fig. 1. Fig. 4 shows a plan of the, feed turning it on the v feed ing it on the feed cam shaft. vertical section on theplane indicated by the '10 which are designed to cut la plurallty of end of the'zfeed` shaft isa held by suitable means in engagement with vthe feed cam 15 which is of common outline The tool 'feed and recontrolled by feed cams, y16 that at its forward a single threading my application August '29th, 1916.

the end of the lever isengagedby one offthe am` surfaces the nsad to V'rock the .feed shaft and cam and the means forV advancing and recam shaft. Fig. 5 1s a 'ye'rtical section onthe dotted line 5 5 on Fig. 4. p ig. 6 is a section on the dotted line- 6-6 on Fig. 3. F ig.7 shows a front elevation ofthe feedcam and a modified .form of means for advancing and returndotted line"8"-8 on Fig. 7.

camand the modified form of controlling mechanism. 10 is a section on the dotted line 10%10 on Fig. 9.

Inthe machine illustrated. the threadingtool 11 is clampedin a holder 12 that'is fastened to the feed shaft 13. Fixedto one shoel 14 that is and` is rotated by the usual mechanism.

F astened to the feed shaft is a rocker arm end has a shoe 17 which is held in engagement with the edge of theprofile cam 18 by a spring 19. The

Fig. 8 is al profilecam is adjustably fastened to the `front of a yoke-shapedsaddle 20 which is plvotally mounted in the frame 21 concentric with the feed shaft. Projecting vrearwardly `from the saddle is alever 22 the end Vof which-is successively engaged by the surfaces 23 of the cut or depth cam 24 that is mounted on the cam shaft'25. The cut cam illustrated is of the type vdescribed States Letters Patent #1,196,308. granhlh on e isfswungvso as turn the toolin towardk the screw blank.

timed that the end ofthe Alever drops into oneofthe spaces 26 allowing the tool to be drawn away from the screw blankasthe' returnfmovement ofy thel tools is bein effected. "Each succeeding project-ione the.

thrust bearing`29 andtliehubv of the cam so as to push the camback on the shaft against in United to rotate therewith but have a lon- 105 etween an anti-frictionv 1 *cainishigher than the `preceding .projection the accompanying drawingsFig'ure 1.

' feed cam. is

an anti-friction bearing 30. Rotatably mounted on the feed cam shaft back of the bearing 30 is a collar 31 that .has ratchet teeth 32. Engaging with these teeth are ratchet teeth 33 on a collar 34 that is fastened to a bushing 35 which is xed in the frame 36 about the feed cam shaft. Projectin vfrom the rotatable collar 31 is an arm 3% which is pivotally connected with an arm 38 that is mounted on an eccentric 39. The eccentric turns on a stud 40 fastened in the frame and it is attached to a disk 41 which has two pins 42 that project into the the ath of a cam block 43 which is fastened l back of the feed cam. The cam block 43; diiringthe revolution of the feed cam engages one of the pins 42 and turns the eccentric Vhalf way around and this through the eccentric arm turns the rotatable toothed the feed camshaft. When thel collar 31 on loosecollar. is turned one way by the eccentric its teeth ridel up on the teeth of the fixed' collarL 34. and this forces the feed cam forward. When the loose collar is turned in the opposite direction its teeth move back into the s aces between the teeth ofthe fixed collar an the feed cam is pushed back by the spring on the feed cam shaft.

These mechanisms so co-act that during or after one return movement of the tool the feedoam is advanced and during or after thel next return movement of the tool the ushed back, so that every alternate forwar feed of the tool adected by the rotation of the feed cam commences back of the oint where the intermediate forward feeds` of the tool caused by the rotation of the cani' commence. This distance is substantially equal to the distance between the two lthreads to be cut and thereby one forward feed of the tool follows one thread groovein cutting. and the next forward feed of the tool followslthe other thread groovein cutting. The cut or depth cam is constructed as usual but` in this case it has twice the common number of notches and cam surfaces, and the notches are so shaped that the tool is not swung up into engagement with the screw blank when the feed cam is back until the cam has be n to feed the tool and the blank has ma cone-half 'of a revolution. By this arrangement the two' threads are cut with a single tool and the threads will start on diametricallyu opposite sides of the blank at the same distance from the oint.

Tlie cam shaft and feed cam shaft illustrated may be rotated by mechanism similar to that described in United States Letters Patent #1,170,694 granted on my application February 8th, 1916.

In the modified construction illustrated instead of rotating the vloose toothed collar for advancing and returning the feed cam, by means of an eccentric as above described, the

disk bearing the pins which are engaged by the cam block on the back of the feed .cam maybe fastened to a pinion 44 which may be meshed with a gear 45 fastened to a sleeve 46 that is rotarily mounted in the frame on the feedcam shaft. Fastened to this gear is a collar 47 'with recesses 48. Held from rotation on the feed cam shaft is a collar 49 with teeth 50. When, during the rotation of the feed camfthe block which it carries engages one of the' pins and causes the rotation of the pinion and gear, the collar 47 is turned with relation to the collar 49 so that at one time the teeth of the latter are in the notches of the former and the feed cam is pushed back by the spring. other time the teeth of the collars ride u on. each other and the feed cam is pushed orward. These parts are so timed that the feed cam is moved back and forward at the same periods as previously described for the purpose of causing the tool to cut first in one of the thread grooves and then in the other of the thread grooves in order to form the two threads.

The invention claimed is A 1. In a screw machine. the combination with a threading tool movable back and orth longitudinally and transversely of the blank to be threaded, of means for feeding the tool longitudinally, means for changing the locality of said feeding means between each feed of the tool, and means for feeding the tooll transversely.

2. In a screw machine the combination with a threadin tool movable back and forth longitudina ly and transversely of the blank to be threaded, of means for feeding the toollongitudinally'-, means for increasing the len h of each alternate feed and decreasing t e lenl h 'of each intermediate feed, andmeans or feeding the tool transverselly.

3. 'n a screw machine the combination with a threadin tool movable back and forth longitudina ly and transversely of the blank to be threaded, of means for feeding the tool longitudinall means operatively connected with the fee ing means for changing the locality of thefeeding means before each feed of the tool, and means for feeding the tool transversely.

4. In, a screw machine the combination with a threadin tool movable back and forth longitudina ly and transversely of the blank to be threaded, of acam for feeding the tool longitudinally, 'means for changing the locality of the cam before each feed of the tool, and means for feeding the tool transversely.

5. In a screw machine the combination with a threading tool movable back and forth longitudinally and transversely of the blank to be threaded, of a cam for feeding the tool longitudinally, means for sliding with a threadin1 tool, means mounted. on the feed cam for operating the position changing means, and means for feeding the tool transversel 6. na screw `thecam back and forth in a line with the v feed of the cam 1n a line with the feed of the tool, an

' tool transversely.

- g y nately advancing eccentric for operating said co-'acting.surfaces, means on the feed cam for actuating said eccentric, and means for feeding the a screw with a tlsfreadinl forth longitudin machine the combination tool movable back and y and transversely of the blank to be threaded, of means for feeding the tool longitudinally, means for alter` and retracting said feeding means between each feed ofthe tool, and means `for feeding the tool transversely.

8. In a screw machine the combination a threading tool movable back and blank to be threaded, of a cam for feeding the tool longitudinally, means for alternately advancingand retracting the cam before each feedofthe tool, and means for feeding the tool transversely.

9. In a screvv machine the combination4 tool movable back and with a vtl'lreadin ily and transverselyof the forth longitudina blank to be threaded, of a calm for feeding the tool longitudinally, mounted to rotate and to move back and forth in a line with the feed of the tool` coacting toothed surfaces adapted to -move the feed ycam in a line with the feedof the tool, means actuated from the feed cam for operating said coacting surfaces, and means for lfeedm the tool transversely.

10. n a screw machine the, combination with. a threading ktool movable' back and said cam being forth longitudinally of" the blank to be threaded, of means for feeding the tool longitudinally, and means operatively connected with thefeeding means for changing the locality of the.,l feed of the tool.

l1. vIn a screw machine thev combination with a threading tool movable back and forth longitudinally of; the blank to be threaded, of a cam for feeding the tocl'longitudinally, means for sliding the cam back and forth in a line with the feed vof the tool, and means mounted on the feed cam for operating Said position changing means.

In' a screw machine the, combination /With a threading tool movable back and forth longitudinally of the blank to be threaded, of means forvfeedingthe tool longitudinally,.and means for increasing the lengthof each alternate feed and decreasing the length of-each intermediate feed. HENRY L SMITH.

feeding means before each 

